Method of making integrated MOS circuits comprising high-voltage MOS transistors, and circuitry for switching power circuits by using such high-voltage MOS transistors.

摘要

Method of making integrated MOS circuits comprising high-voltage MOS transistors (20, 21, 22), in which zones which contain drift zones (11-15) and have a conductivity type opposite to the conductivity type of the semiconductor substrate are produced by implantation and post- diffusion in a single doping step in a lightly doped semiconductor substrate (10) with a size such that they surround at least the drains (32, 36) on all sides or the entire transistors (21, 22) on all sides. Complementary high-voltage MOS transistors (22) are formed in the zones (13) containing the drift zones (17) surrounding the drains (36) on all sides and having a doping similar to the semiconductor substrate. Additionally, low-voltage MOS transistors (23, 24) and bipolar transistors (25) can be formed on one substrate (10) and in the same steps of the method. Linking complementary logic circuits containing low-voltage transistors (23, 24) to high-voltage MOS transistors (110, 120, 121) via high-voltage driver transistors (116, 130, 133) on one substrate (10) using voltage pulses at the gate capacitances (111, 112, 124-127) results in a relatively small-area, low-power circuit for the fast switching of pulsating high voltage (Figure 1).